The present invention concerns apparatus and methods for joining connectors or other electrical components, having solder-less pin-type or other terminals, to substrates, such as printed circuit boards, or to other components.
When joining a multi-terminal component, such as a connector, to a substrate by soldering, particularly a substrate with internally plated holes, special provisions have often been required, such as shown in U.S. Pat. Nos. 4,597,625; 4,802,862; 4,883,435; 5,139,448; and 5,334,059. Such components have terminals which do not carry solder, so that these situations have generally required special means for providing solder to the component terminals and to contact pads on the substrate, and/or to the electro-plated lining of holes in the substrate. One approach to providing solder to the component terminals and contact pads is to provide solder paste in and around the particular area, such as a hole. However, this approach generally does not provide a sufficient volume of solder to properly join the component terminals and contact pads.
Such connectors commonly have their pins gold-plated, which must then interface gold-to-gold with gold plating on the substrate. Accordingly, the connectors cannot be wave soldered, and are commonly either hand-soldered or have solder doughnuts placed on each terminal pin and then reflowed with hot air. For connectors with a large number of terminals, this assembly method is costly.
The present invention provides a simple and inexpensive way of applying solder in such situations, which may readily be automated, without requiring separately applying solder paste to the component terminals or to the plated holes or contact pads of the substrate.